First, the eGO (or the Tornado, Riva, Hello 016, VGO, KGO, Inferno, Elegant, Leo, etc.) is not really a "
mod." It is a regular e-cig with a fatter and much higher mAh battery than any which had come before. [See
this article for more about these models.] A mod is a housing for generic
batteries. [See my
Wonderful World of Mods in the ECF Library.]
My first
mod was the Prodigy V1, because it was one of the few mods available at the time and was 5V. It was very good, albeit finicky.
My first "fat batt" (as I call the eGO-types) was CigEasy's Elegant (for Kr8 cartomizers and the 901 atty), because I was asked to review it. It is an excellent performer. My favorite fat batt is the penstyle-type Leo, because I love penstyle atomizers (and the Leo's is outstanding).